Overview
When trying to run an Oracle query, an Oracle user may experience the error ORA-12805: Parallel Query Server Died Unexpectedly. This error occurs when an instance of Oracle’s Parallel Query Server unexpectedly dies during processing. This document will explain what ORA-12805 is, what cases can cause it, and how to fix it.
What is ORA-12805
ORA-12805 is an Oracle error that occurs when an instance of Oracle’s Parallel Query Server unexpectedly dies during processing. The Parallel Query Server (PQS) is a part of Oracle's server that enables parallel query execution, which includes merging and merging results from collections of services into a single result set.
When Does ORA-12805 Occur?
ORA-12805 may occur when the query cannot process in time and the session is killed or disconnected. It may also occur when the server resources are insufficient.
How to Fix ORA-12805
Increase the amount of time allocated for query processing: One way to fix ORA-12805 is to increase the amount of time allocated for query processing. This can be done by modifying the ‘session_timeout’ parameter in the ‘sqlnet.ora’ file.
Increase the amount of memory allocated for parallel query processing: Another way to fix ORA-12805 is to increase the amount of memory allocated for parallel query processing. This can be done by increasing the value of ‘pga_aggregate_target’ in the ‘init.ora’ file.
Increase the number of SQL query processes: The number of SQL query processes allocated can be increased by changing the ‘parallel_max_servers’ parameter in the ‘init.ora’ file.
FAQ
Q: What is ORA-12805?
A: ORA-12805 is an Oracle error that occurs when an instance of Oracle’s Parallel Query Server unexpectedly dies during processing.
Q: When does ORA-12805 occur?
A: ORA-12805 may occur when the query cannot process in time and the session is killed or disconnected. It may also occur when the server resources are insufficient.
Q: How can I fix ORA-12805?
A: To fix ORA-12805, you can increase the amount of time allocated for query processing, increase the amount of memory allocated for parallel query processing, and increase the number of SQL query processes.